For that study, and all the experiments presented in this paper, we used the Convolution Neural Networks of [1]} to take into account the small processing power on mobile devices. The studies [1]} showed that a model 196-16C_4M_1024D gives the best result over a set of state-of-the-art-model. It includes 196 filters of a 16x1 convolution layer followed by a 1x4 max pooling layer, then by 1024 units of a dense layer and finally a softmax layer.
